@article{BrumbergBlazhenetsSchroeteretal.2019, author = {Brumberg, Joachim and Blazhenets, Ganna and Schr{\"o}ter, Nils and Frings, Lars and Jost, Wolfgang H. and Lapa, Constantin and Meyer, Philipp T.}, title = {Imaging cardiac sympathetic innervation with MIBG: linear conversion of the heart-to-mediastinum ratio between different collimators}, series = {EJNMMI Physics}, volume = {6}, journal = {EJNMMI Physics}, doi = {10.1186/s40658-019-0250-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221675}, year = {2019}, abstract = {Background The heart-to-mediastinum (H/M) ratio is a commonly used parameter to measure cardiac I-123 metaiodobenzylguanidine (MIBG) uptake. Since the H/M ratio is substantially influenced by the collimator type, we investigated whether an empirical linear conversion of H/M ratios between camera systems with low-energy (LE) and medium-energy (ME) collimator is possible. Methods We included 18 patients with parkinsonism who were referred to one of the two participating molecular imaging facilities for the evaluation of cardiac sympathetic innervation by MIBG scintigraphy. Two consecutive planar image datasets were acquired with LE and ME collimators at 4 h after MIBG administration. Linear regression analyses were performed to describe the association between the H/M ratios gained with both collimator settings, and the accuracy of a linear transfer of the H/M ratio between collimators and across centers was assessed using a leave-one-out procedure. Results H/M ratios acquired with LE and ME collimators showed a strong linear relationship both within each imaging facility (R\(^2\) = 0.99, p < 0.001 and R\(^2\) = 0.90, p < 0.001) and across centers (H/M-LE = 0.41 × H/M-ME + 0.63, R\(^2\) = 0.97, p < 0.001). A linear conversion of H/M ratios between collimators and across centers was estimated to be very accurate (mean absolute error 0.05 ± 0.04; mean relative absolute error 3.2 ± 2.6\%). Conclusions The present study demonstrates that a simple linear conversion of H/M ratios acquired with different collimators is possible with high accuracy. This should greatly facilitate the exchange of normative data between settings and pooling of data from different institutions.}, language = {en} } @article{RascheKumarGershneretal.2019, author = {Rasche, Leo and Kumar, Manoj and Gershner, Grant and Samant, Rohan and Van Hemert, Rudy and Heidemeier, Anke and Lapa, Constantin and Bley, Thorsten and Buck, Andreas and McDonald, James and Hillengass, Jens and Epstein, Joshua and Thanendrarajan, Sharmilan and Schinke, Carolina and van Rhee, Frits and Zangari, Maurizio and Barlogie, Bart and Davies, Faith E. and Morgan, Gareth J. and Weinhold, Niels}, title = {Lack of Spleen Signal on Diffusion Weighted MRI is associated with High Tumor Burden and Poor Prognosis in Multiple Myeloma: A Link to Extramedullary Hematopoiesis?}, series = {Theranostics}, volume = {9}, journal = {Theranostics}, number = {16}, doi = {10.7150/thno.33289}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224982}, pages = {4756-4763}, year = {2019}, abstract = {Due to the low frequency of abnormalities affecting the spleen, this organ is often overlooked during radiological examinations. Here, we report on the unexpected finding, that the spleen signal on diffusion-weighted MRI (DW-MRI) is associated with clinical parameters in patients with plasma cell dyscrasias. Methods: We investigated the spleen signal on DW-MRI together with clinical and molecular parameters in 295 transplant-eligible newly diagnosed Multiple Myeloma (NDMM) patients and in 72 cases with monoclonal gammopathy of undetermined significance (MGUS). Results: Usually, the spleen is the abdominal organ with the highest intensities on DW-MRI. Yet, significant signal loss on DW-MRI images was seen in 71 of 295 (24\%) NDMM patients. This phenomenon was associated with the level of bone marrow plasmacytosis (P=1x10(-10)) and International Staging System 3 (P=0.0001) but not with gain(1q), and del(17p) or plasma cell gene signatures. The signal was preserved in 72 individuals with monoclonal gammopathy of undetermined significance and generally re-appeared in MM patients responding to treatment, suggesting that lack of signal reflects increased tumor burden. While absence of spleen signal in MM patients with high risk disease defined a subgroup with very poor outcome, re-appearance of the spleen signal after autologous stem cell transplantation was seen in patients with improved outcome. Our preliminary observation suggests that extramedullary hematopoiesis in the spleen is a factor that modifies the DW-MRI signal of this organ. Conclusions: The DW-MRI spleen signal is a promising marker for tumor load and provides prognostic information in MM.}, language = {en} } @article{ScherthanLeeMausetal.2019, author = {Scherthan, Harry and Lee, Jin-Ho and Maus, Emanuel and Schumann, Sarah and Muhtadi, Razan and Chojowski, Robert and Port, Matthias and Lassmann, Michael and Bestvater, Felix and Hausmann, Michael}, title = {Nanostructure of clustered DNA damage in leukocytes after in-solution irradiation with the alpha emitter Ra-223}, series = {Cancers}, volume = {11}, journal = {Cancers}, number = {12}, issn = {2072-6694}, doi = {10.3390/cancers11121877}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193038}, year = {2019}, abstract = {Background: Cancer patients are increasingly treated with alpha-particle-emitting radiopharmaceuticals. At the subcellular level, alpha particles induce densely spaced ionizations and molecular damage. Induction of DNA lesions, especially clustered DNA double-strand breaks (DSBs), threatens a cell's survival. Currently, it is under debate to what extent the spatial topology of the damaged chromatin regions and the repair protein arrangements are contributing. Methods: Super-resolution light microscopy (SMLM) in combination with cluster analysis of single molecule signal-point density regions of DSB repair markers was applied to investigate the nano-structure of DNA damage foci tracks of Ra-223 in-solution irradiated leukocytes. Results: Alpha-damaged chromatin tracks were efficiently outlined by γ-H2AX that formed large (super) foci composed of numerous 60-80 nm-sized nano-foci. Alpha damage tracks contained 60-70\% of all γ-H2AX point signals in a nucleus, while less than 30\% of 53BP1, MRE11 or p-ATM signals were located inside γ-H2AX damage tracks. MRE11 and p-ATM protein fluorescent tags formed focal nano-clusters of about 20 nm peak size. There were, on average, 12 (±9) MRE11 nanoclusters in a typical γ-H2AX-marked alpha track, suggesting a minimal number of MRE11-processed DSBs per track. Our SMLM data suggest regularly arranged nano-structures during DNA repair in the damaged chromatin domain.}, language = {en} } @article{DaViaSolimandoGaritanoTrojaolaetal.2019, author = {Da Vi{\`a}, Matteo Claudio and Solimando, Antonio Giovanni and Garitano-Trojaola, Andoni and Barrio, Santiago and Munawar, Umair and Strifler, Susanne and Haertle, Larissa and Rhodes, Nadine and Vogt, Cornelia and Lapa, Constantin and Beilhack, Andreas and Rasche, Leo and Einsele, Hermann and Kort{\"u}m, K. Martin}, title = {CIC Mutation as a Molecular Mechanism of Acquired Resistance to Combined BRAF-MEK Inhibition in Extramedullary Multiple Myeloma with Central Nervous System Involvement}, series = {The Oncologist}, volume = {25}, journal = {The Oncologist}, number = {2}, doi = {10.1634/theoncologist.2019-0356}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219549}, pages = {112-118}, year = {2019}, abstract = {Combined MEK-BRAF inhibition is a well-established treatment strategy in BRAF-mutated cancer, most prominently in malignant melanoma with durable responses being achieved through this targeted therapy. However, a subset of patients face primary unresponsiveness despite presence of the activating mutation at position V600E, and others acquire resistance under treatment. Underlying resistance mechanisms are largely unknown, and diagnostic tests to predict tumor response to BRAF-MEK inhibitor treatment are unavailable. Multiple myeloma represents the second most common hematologic malignancy, and point mutations in BRAF are detectable in about 10\% of patients. Targeted inhibition has been successfully applied, with mixed responses observed in a substantial subset of patients mirroring the widespread spatial heterogeneity in this genomically complex disease. Central nervous system (CNS) involvement is an extremely rare, extramedullary form of multiple myeloma that can be diagnosed in less than 1\% of patients. It is considered an ultimate high-risk feature, associated with unfavorable cytogenetics, and, even with intense treatment applied, survival is short, reaching less than 12 months in most cases. Here we not only describe the first patient with an extramedullary CNS relapse responding to targeted dabrafenib and trametinib treatment, we furthermore provide evidence that a point mutation within the capicua transcriptional repressor (CIC) gene mediated the acquired resistance in this patient.}, language = {en} } @article{WernerWakabayashiChenetal.2019, author = {Werner, Rudolf A. and Wakabayashi, Hiroshi and Chen, Xinyu and Hayakawa, Nobuyuki and Lapa, Constantin and Rowe, Steven P. and Javadi, Mehrbod S. and Robinson, Simon and Higuchi, Takahiro}, title = {Ventricular distribution pattern of the novel sympathetic nerve PET radiotracer \(^{18}\)F-LMI1195 in Rabbit Hearts}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-53596-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202707}, pages = {17026}, year = {2019}, abstract = {We aimed to determine a detailed regional ventricular distribution pattern of the novel cardiac nerve PET radiotracer \(^{18}\)F-LMI1195 in healthy rabbits. Ex-vivo high resolution autoradiographic imaging was conducted to identify accurate ventricular distribution of \(^{18}\)F-LMI1195. In healthy rabbits, \(^{18}\)F-LMI1195 was administered followed by the reference perfusion marker \(^{201}\)Tl for a dual-radiotracer analysis. After 20 min of \(^{18}\)F-LMI1195 distribution time, the rabbits were euthanized, the hearts were extracted, frozen, and cut into 20-μm short axis slices. Subsequently, the short axis sections were exposed to a phosphor imaging plate to determine \(^{18}\)F-LMI1195 distribution (exposure for 3 h). After complete \(^{18}\)F decay, sections were re-exposed to determine 201Tl distribution (exposure for 7 days). For quantitative analysis, segmental regions of Interest (ROIs) were divided into four left ventricular (LV) and a right ventricular (RV) segment on mid-ventricular short axis sections. Subendocardial, mid-portion, and subepicardial ROIs were placed on the LV lateral wall. \(^{18}\)F-LMI1195 distribution was almost homogeneous throughout the LV wall without any significant differences in all four LV ROIs (anterior, posterior, septal and lateral wall, 99 ± 2, 94 ± 5, 94 ± 4 and 97 ± 3\%LV, respectively, n.s.). Subepicardial \(^{201}\)Tl uptake was significantly lower compared to the subendocardial portion (subendocardial, mid-portion, and subepicardial activity: 90 ± 3, 96 ± 2 and *80 ± 5\%LV, respectively, *p < 0.01 vs. mid-portion). This was in contradistinction to the transmural wall profile of \(^{18}\)F-LMI1195 (90 ± 4, 96 ± 5 and 84 ± 4\%LV, n.s.). A slight but significant discrepant transmural radiotracer distribution pattern of \(^{201}\)Tl in comparison to \(^{18}\)F-LMI1195 may be a reflection of physiological sympathetic innervation and perfusion in rabbit hearts.}, language = {en} } @article{BreunMonoranuKessleretal.2019, author = {Breun, Maria and Monoranu, Camelia M. and Kessler, Almuth F. and Matthies, Cordula and L{\"o}hr, Mario and Hagemann, Carsten and Schirbel, Andreas and Rowe, Steven P. and Pomper, Martin G. and Buck, Andreas K. and Wester, Hans-J{\"u}rgen and Ernestus, Ralf-Ingo and Lapa, Constantin}, title = {[\(^{68}\)Ga]-Pentixafor PET/CT for CXCR4-mediated imaging of vestibular schwannomas}, series = {Frontiers in Oncology}, volume = {9}, journal = {Frontiers in Oncology}, number = {503}, doi = {10.3389/fonc.2019.00503}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201863}, year = {2019}, abstract = {We have recently demonstrated CXCR4 overexpression in vestibular schwannomas (VS). This study investigated the feasibility of CXCR4-directed positron emission tomography/computed tomography (PET/CT) imaging of VS using the radiolabeled chemokine ligand [\(^{68}\)Ga]Pentixafor. Methods: 4 patients with 6 primarily diagnosed or pre-treated/observed VS were enrolled. All subjects underwent [\(^{68}\)Ga]Pentixafor PET/CT prior to surgical resection. Images were analyzed visually and semi-quantitatively for CXCR4 expression including calculation of tumor-to-background ratios (TBR). Immunohistochemistry served as standard of reference in three patients. Results: [\(^{68}\)Ga]Pentixafor PET/CT was visually positive in all cases. SUV\(_{mean}\) and SUV\(_{max}\) were 3.0 ± 0.3 and 3.8 ± 0.4 and TBR\(_{mean}\) and TBR\(_{max}\) were 4.0 ± 1.4 and 5.0 ± 1.7, respectively. Histological analysis confirmed CXCR4 expression in tumors. Conclusion: Non-invasive imaging of CXCR4 expression using [\(^{68}\)Ga]Pentixafor PET/CT of VS is feasible and could prove useful for in vivo assessment of CXCR4 expression.}, language = {en} } @article{WernerKircherHiguchietal.2019, author = {Werner, Rudolf A. and Kircher, Stefan and Higuchi, Takahiro and Kircher, Malte and Schirbel, Andreas and Wester, Hans-J{\"u}rgen and Buck, Andreas K. and Pomper, Martin G. and Rowe, Steven P. and Lapa, Constantin}, title = {CXCR4-directed imaging in solid tumors}, series = {Frontiers in Oncology}, volume = {9}, journal = {Frontiers in Oncology}, number = {770}, issn = {2234-943X}, doi = {10.3389/fonc.2019.00770}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-195678}, year = {2019}, abstract = {Despite histological evidence in various solid tumor entities, available experience with CXCR4-directed diagnostics and endoradiotherapy mainly focuses on hematologic diseases. With the goal of expanding the application of CXCR4 theranostics to solid tumors, we aimed to elucidate the feasibility of CXCR4-targeted imaging in a variety of such neoplasms. Methods: Nineteen patients with newly diagnosed, treatment-na{\"i}ve solid tumors including pancreatic adenocarcinoma or neuroendocrine tumor, cholangiocarcinoma, hepatocellular carcinoma, renal cell carcinoma, ovarian cancer, and prostate cancer underwent [\(^{68}\)Ga]Pentixafor PET/CT. CXCR4-mediated uptake was assessed both visually and semi-quantitatively by evaluation of maximum standardized uptake values (SUV\(_{max}\)) of both primary tumors and metastases. With physiologic liver uptake as reference, tumor-to-background ratios (TBR) were calculated. [\(^{68}\)Ga]Pentixafor findings were further compared to immunohistochemistry and [\(^{18}\)F]FDG PET/CT. Results: On [\(^{68}\)Ga]Pentixafor PET/CT, 10/19 (52.6\%) primary tumors were visually detectable with a median SUVmax of 5.4 (range, 1.7-16.0) and a median TBR of 2.6 (range, 0.8-7.4), respectively. The highest level of radiotracer uptake was identified in a patient with cholangiocarcinoma (SUVmax, 16.0; TBR, 7.4). The relatively low uptake on [\(^{68}\)Ga]Pentixafor was also noted in metastases, exhibiting a median SUVmax of 4.5 (range, 2.3-8.8; TBR, 1.7; range, 1.0-4.1). A good correlation between uptake on [\(^{68}\)Ga]Pentixafor and histological derived CXCR4 expression was noted (R = 0.62, P < 0.05). In the 3 patients in whom [\(^{18}\)F]FDG PET/CT was available, [\(^{68}\)Ga]Pentixafor exhibited lower uptake in all lesions. Conclusions: In this cohort of newly diagnosed, treatment-na{\"i}ve patients with solid malignancies, CXCR4 expression as detected by [\(^{68}\)Ga]Pentixafor-PET/CT and immunohistochemistry was rather moderate. Thus, CXCR4-directed imaging may not play a major role in the management of solid tumors in the majority of patients.}, language = {en} } @phdthesis{SoaresMachado2019, author = {Soares Machado, J{\´e}ssica}, title = {Dosimetry-based Assessment of Radiation-associated Cancer risk for \(^9\)\(^9\)\(^m\)Tc-MAG3 Scans in Infants and Optimization of Administered Activities for \(^6\)\(^8\)Ga-labelled Peptides in Children and Adolescents}, doi = {10.25972/OPUS-19264}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-192640}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {In 2006, 0.18 Mio pediatric nuclear medicine diagnostic exams were performed worldwide. However, for most of the radiopharmaceuticals used data on biokinetics and, as a consequence on dosimetry, are missing or have not been made publicly available. Therefore, most of the dosimetry assessments presented today for diagnostic agents in children and adolescents rely on the biokinetics data of adults. Even for one of the most common nuclear medicine exams for this patient group, renal scintigraphy with 99mTc-MAG3 for assessing renal function measured data on biokinetics is available only from a study performed on four children of different ages. In particular, renal scans are among the most frequent exams performed on infants and toddlers. Due to the young age, this patient group can be classified as a risk group with a higher probability of developing stochastic radiation effects compared to adults. As there are only limited data on biokinetics and dosimetry in this patient group, the aim of this study is to reassess the dosimetry and the associated radiation risk for a larger number of infants undergoing 99mTc-MAG3 renal scans based on a retrospective analysis of existing patient data. Data were collected retrospectively from 34 patients younger than 20 months with normal (20 patients) and abnormal renal function (14 patients) undergoing 99mTc-MAG3 scans. The patient-specific organ activity was estimated based on a retrospective calibration which was performed based on a set of two 3D-printed infant kidneys (newborns: 8.6 ml; 1-year-old: 23.4 ml) filled with known activities. Both phantoms were scanned at different positions along the anteroposterior axis inside a water phantom, providing depth- and size-dependent attenuation correction factors for planar imaging. Time-activity curves were determined by drawing kidney, bladder, and whole body regions-of-interest for each patient, and subsequently applying the calibration factor for conversion of counts to activity. Patient-specific time-integrated activity coefficients were obtained by integrating the organ-specific time-activity curves. Absorbed and effective dose coefficients for each patient were assessed with OLINDA/EXM for the provided newborn and 1-year-old phantom. Based on absorbed dose values, the radiation risk estimation was performed individually for each of the 34 patients with the National Cancer Institute's Radiation Risk Assessment Tool. The patients' organ-specific mean absorbed dose coefficients for the patients with normal renal function were 0.04±0.03 mGy/MBq for the kidneys and 0.27±0.24 mGy/MBq for the bladder. This resulted in a mean effective dose coefficient of 0.02±0.02 mSv/MBq. Based on the dosimetry results, the evaluation of the excess lifetime risk (ELR) for the development of radiation-induced cancer showed that the group of newborns has an ELR of 16.8 per 100,000 persons, which is higher in comparison with the 1-year-old group with an ELR of 14.7 per 100,000 persons. With regard to the 14 patients with abnormal renal function, the mean values for the organ absorbed dose coefficients for the patients were: 0.40±0.34 mGy/MBq for the kidneys and 0.46±0.37 mGy/MBq for the bladder. The corresponding effective dose coefficients (mSv/MBq) was: 0.05±0.02 mSv/MBq. The mean ELR (per 100,000 persons) for developing cancer from radiation exposure for patients with abnormal renal function was 29.2±18.7 per 100,000 persons. As a result, the radiation-associated stochastic risk increases with the organ doses, taking age- and gender-specific influences into account. Overall, the lifetime radiation risk associated with the 99mTc-MAG3 scans is very low in comparison to the general population risk for developing cancer. Furthermore, due to the increasing demand for PET-scans in children and adolescents with 68Ga-labelled peptides, in this work published data sets for those compounds were analyzed to derive recommendations for the administered activities in children and adolescents. The recommendation for the activities to be administered were based on the weight-independent effective dose model, proposed by the EANM Pediatric Dosage Card for application in pediatric nuclear medicine. The aim was to derive recommendations on administered activities for obtaining age-independent effective doses. Consequently, the corresponding weight-dependent effective dose coefficients were rescaled according to the formalism of the EANM dosage card, to determine the radiopharmaceutical class of 68Ga-labeled peptides ("multiples"), and to calculate the baseline activities based on the biokinetics of these compounds and an upper limit of the administered activity of 185 MBq for an adult. Analogous to 18F-fluoride, a minimum activity of 14 MBq is recommended. As a result, for those pediatric nuclear medicine applications involving 68Ga-labeled peptides, new values for the EANM dosage card were proposed and implemented based on the results derived in this work. Overall, despite the low additional radiation-related cancer risk, all efforts should be undertaken to optimize administered activities in children and adolescents for obtaining sufficient diagnostic information with minimal associated radiation risk.}, subject = {Biokinetics}, language = {en} } @phdthesis{BrumberggebIchouh2019, author = {Brumberg [geb. Ichouh], Dalma}, title = {\(^{11}\)C-MET und \(^{18}\)F-FDG: \(In\) \(vitro\) Vergleich zur Bildgebung beim Multiplen Myelom im Kontext biologischer Charakteristika}, doi = {10.25972/OPUS-18184}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181843}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Das Multiple Myelom ist eine h{\"a}matologische Erkrankung, die durch die Proliferation von Plasmazellen und die Produktion von Antik{\"o}rpern oder deren Leichtketten gekennzeichnet ist. Eine fr{\"u}he Diagnosestellung durch Detektion sowohl intra- als auch extramedull{\"a}rer Manifestationen ist f{\"u}r die Einleitung einer effektiven Therapie von entscheidender Bedeutung. Ebenso bedeutsam ist ein wirksames Therapiemonitoring. Wichtige diagnostische Modalit{\"a}ten sind bei beiden Fragestellungen tomografische, bildgebende Verfahren. Hierbei wurde die Effektivit{\"a}t der 18F-FDG-PET/CT im Rahmen der Diagnose, des Stagings und der Prognoseabsch{\"a}tzung bereits nachgewiesen. Dennoch ist ihr klinischer Nutzen durch die geringe Sensitivit{\"a}t bei Detektion von diffusem Knochenmarksbefall und Vorliegen sowohl falsch positiver als auch falsch negativer Befunde limitiert. Die vorliegende Arbeit hat untersucht, ob der aminos{\"a}urebasierte Tracer 11C-MET {\"u}ber spezifische Eigenschaften verf{\"u}gt, die eine h{\"o}here Sensitivit{\"a}t und Spezifit{\"a}t in der Detektion von Myelomzellen erm{\"o}glichen und ob der Radioligand dem etablierten Glukoseanalogon 18F-FDG {\"u}berlegen ist. Hierf{\"u}r wurden drei etablierte humane Myelomzelllinien, sowohl nativ als auch nach 48-st{\"u}ndiger Therapie mit dem Proteasominhibitor Carfilzomib, mit 18F-FDG und 11C-MET inkubiert und mithilfe eines Gammastrahlungsz{\"a}hlers beurteilt. Zudem wurde untersucht, ob die Traceraufnahme mit spezifischen Charakteristika der Tumorbiologie korreliert. So wurde die Oberfl{\"a}chenexpression von CD138 und CXCR4, die intrazellul{\"a}re Expression der Leichtketten κ/λ und die Proliferation der Zelllinien mittels Durchflusszytometrie vor und nach Behandlung mit Carfilzomib eruiert. Die unbehandelten Zellen zeigten, verglichen zu 18F-FDG, bereits nach k{\"u}rzester Inkubationsdauer eine 3-3,5-fach h{\"o}here 11C-MET Retention. Weiterhin zeigte sich die 11C-MET-Aufnahme nach Behandlung aller Zellreihen insgesamt marginal h{\"o}her als die 18F-FDG-Aufnahme, w{\"a}hrend die Reduktion der 11C-MET-Anreicherung im pr{\"a}- zu posttherapeutischen Vergleich f{\"u}r alle drei Zelllinien signifikant war. Eine m{\"o}gliche Erkl{\"a}rung f{\"u}r diese Beobachtungen liefert die Myelombiologie: eine erh{\"o}hte Aufnahme der radioaktiv markierten Aminos{\"a}ure durch MM-Zellen k{\"o}nnte durch eine Zunahme der Zellproliferation und insbesondere durch eine Steigerung der Proteinsynthese im Rahmen der {\"u}berschießenden Produktion von M-Protein bedingt sein. In Zusammenschau k{\"o}nnte 11C-MET mit h{\"o}herer Sensitivit{\"a}t Myelommanifestationen detektieren, wodurch ggf. L{\"a}sionen mit geringem Metabolismus dargestellt und eine bessere Beurteilung des Krankheitspogresses erfolgen k{\"o}nnte. Zudem bietet f{\"u}r den klinischen Einsatz die - verglichen zu 18F-FDG - gr{\"o}ßere Differenz der 11C-MET-Retention zwischen pr{\"a}- und posttherapeutischer Messung die M{\"o}glichkeit einer besseren Beurteilbarkeit des Therapieansprechens. 11C-MET birgt ggf. das Potential auch minimale aktive Restherde zu detektieren und damit Patienten einem individualisierten Therapiekonzept zuzuf{\"u}hren. Ein Zusammenhang zwischen den untersuchten Biomarkern und der 11C-MET Retention bzw. deren Abnahme nach Behandlung konnte nicht gezeigt werden. Somit sollten f{\"u}r 11C-MET andere Biomarker herangezogen werden, um diese mit der Bildgebung zu korrelieren und zu bewerten.}, subject = {Multiples Myelom}, language = {de} } @article{WernerOrdonezSanchezBautistaetal.2019, author = {Werner, Rudolf A. and Ordonez, Alvaro A. and Sanchez-Bautista, Julian and Marcus, Charles and Lapa, Constantin and Rowe, Steven P. and Pomper, Martin G. and Leal, Jeffrey P. and Lodge, Martin A. and Javadi, Mehrbod S. and Jain, Sanjay K. and Higuchi, Takahiro}, title = {Novel functional renal PET imaging with 18F-FDS in human subjects}, series = {Clinical Nuclear Medicine}, volume = {44}, journal = {Clinical Nuclear Medicine}, number = {5}, issn = {0363-9762}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-174634}, pages = {410-411}, year = {2019}, abstract = {The novel PET probe 2-deoxy-2-18F-fluoro-D-sorbitol (18F-FDS) has demonstrated favorable renal kinetics in animals. We aimed to elucidate its imaging properties in two human volunteers. 18F-FDS was produced by a simple one-step reduction from 18F-FDG. On dynamic renal PET, the cortex was delineated and activity gradually transited in the parenchyma, followed by radiotracer excretion. No adverse effects were reported. Given the higher spatiotemporal resolution of PET relative to conventional scintigraphy, 18F-FDS PET offers a more thorough evaluation of human renal kinetics. Due to its simple production from 18F-FDG, 18F-FDS is virtually available at any PET facility with radiochemistry infrastructure.}, subject = {Positronen-Emissions-Tomografie}, language = {en} }